Sound recording and producing method



July 11, 1933. 5 w r 1,917,279

SOUND RECORDING AND PRODUCING METHOD Filed June 30, 1930 5 Sheets-$heet l n ooo AH] N O O O @D @O @O @D w IINVENTOR Stewart 6. Wlu'tmm BY r ATTORN EYS July 11, 1933. s. c. WHITMAN 1,917,279

SOUND RECORDING AND PRODUCING METHOD 7 Filed Jun 50, 1950 5 Sheets-Sheet 2 B Battery B Butte r Stewart a Whitman INVENTOR BYQ,

ATTORNEYS July 11, 1933. s. c. WHITMAN SOUND RECORDING AND PRODUCING METHOD Filed June 30', 1930 5 SheetsSheet 3 INVENTOR Stewart 61 Wiutmm 6 4 2 6! BY r ATTORNEYS July 11, 1933. s c w n' 1,917,279

SOUND RECORDING AND PRODUCING METHOD Filed June 50, 1930 5 Sheets-Sheet 4 wV m m flmmrt 6. Whiz/1m INVENTOR I BY ATTORNEYS July 11, 1933. s. c. WHITMAN SOUND RECORDING AND PRODUCING METHOD 5 Sheets-Sheet 5 Filed June 50, 1930 UUUUUUUD 1 W llIlllllllllllllllllllllllllllllll lllllllllllllllllllllllllllllllll I I I I I U m U n m U W m. U m M U tm O U w n U W A U W w m D S S l D U U U Patented July 11, 1933 1,917,279. PATENT OFFICE STEWART c. WHITMAN, on new i on m v. Y., nssisuoa or ONE-near ro enonen srrncxnnronn, or new YORK, N. Y.

', scum) nnoonnme AND rnonucrne Mn'rnon Application filed. June 30,

q air. It is well known that the"illumination from such a discharge is highly actinic and can be used to advantagephotographically. The method of using means for keeping a light discharge device operating at a substant'i'ally constant illumination and'modulating this constant illumination withthe output from a speech amplifier is also known.

. The passage of a steady discharge through the light device,,however, results in sputter- 2 ing and ground noises when recorded upon a film. By the use of. a high frequency carrier to operate the light discharge device, these same noises are present but sincelthe light device is extinguished and lighted under 39 the influence of this high frequency oscillating currentat a rate which is above audibility, these objectionable noises are eliminated. This method of illuminating the light device isespecially valuable in the case of the presentinvention, since an unshielded gap discharge lighting device is used becausefthe sputtering and ground noises described above are intensified in this case.

As I only use the impulses from the sound 4 amplifier, the electrical drainage on the sound amplifier is. extremely small. The amplifier proper just emits audiofrequency impulses. These impulsesare impressed upon a transformer or choke which impedance matches the impedance of the sound amplifier output. It is then passed through a power supply and modulating device. This modulating.

device also acts as a mixer for the mixture of audlo-frequency impulses and high frequency electrical energy. This device uses theaudio-frequency impulses to control the high frequency electrical energy.

In the accompanying drawings forming a part of this application,

Fig. 1 is a graphic view consisting of a 1930. Serial No. 465,024.

microphone; a sound amplifier a separate source of electrical energy; tube container for the discharge electrodes and camera; showing the apparatus employed for re cording sound on a photo-sensitized motion picture film. p v V i Fig. 2is a similar View consisting of a sound amplifier; a motion picture projection machine; a motion picture screen and horns; showing the apparatus employed for projecting sound. 7

Fig. 3 is a schematic diagram consisting of asound amplifier; a special transformer; a

high tension spark coil; anda high frequency buzzer showing the output for sparkdis- 7 chargela f Fig. 4 is a schematic diagram consisting of a sound amplifier; a specially wound choke with a suitable metal core; and a high tension spark coil with a high frequencybuzzer; 7 showing the output for spark discharge.

i Fig. 5 isa graphicview consisting ofa sound amplifier output; and an oscillating circuit in connection with high frequency coils with two points of discharge. 30

Fig. 6 is a. similar view consisting of a sound amplifier output; and an oscillating circuit in connection with high frequency coils with one .point of discharge.

Fig. 7 is a similar view consisting of a sound amplifier output; and an oscillating circuit in connection with high frequency coils withone point of discharge close to a photo-sensitized motion picture film.

Fig. 8 is a similar view showing a microphone; an amplifier; a modulating device and separate source of electrical energy; a sound recording chamber; a condensing lens combination; a slit; alens combination; and a photo-sensitized motion picture film.

Fig. 9 is a similar view showing a microphone a sound amplifier; a modulating device and separate source of electrical energy; an electrical discharge against a slit; a condensing'. lens; a lens combination and a 1 photo-sensitized motion picture film.

Fig. 10 is a similar view showing a microphone; a sound amplifier; a modulating device and separate source of electrical energy;

a sound recording chamber; a prismatic lens; 10 a lens combination and a photo-sensitized motion picture film. v

Fig. 11 is a similar view showing a microphone; a sound amplifier; a modulating device and separate source of electrical energy; 11

a sound recording chamber; a prismatic lens; and a photo-sensitized motion picture film.

Fig. 12 is a similar view showing a microphone; a sound amplifier; a modulating device and separate source of electrical energy; a sound recording chamber; a condensing lens in combination with aslit having a cushion mounting; and a photo-sensitized motion picture film.

Fig. 13 is plan View showing sound recorded on both marginal edges of a sixteen millimeter photo-sensitized motion picture film.

Fig. 14 is a similar view showing sound recorded inside the marginal edge of a sixteen millimeter ph0to-sensitized motion picture film.

Fig. 15 is a similar view showing sound recorded inside. the marginal edge of a thirtyfive millimeter photo-sensitized motion picture film.

Fig. 16 shows a photo-sensitized motion picture film using the full space inside both marginal edges.

Fig. 17 is an enlarged plan View showing sound recorded inside the marginal edge of a seventy-two millimeter photo-sensitized motion picture film.

Fig. 18 is a plan view showing sound recorded inside the marginal edge of a photosensitized mot-ion picture film adjacent to a motion picture running horizontally.

In describing my invention covering a method for recording sound on photo-sensitized motion picture films, I shall refer to the drawings in which similar reference characters designate corresponding parts throughout the several views and in which 1 designates a microphone, where sound impulses are impressed, connected to an amplifier 2 where the sound impulses from the microphone are amplified. These amplified sound impulses are passed to an oscillator and modulator 3 which serves as a separate source of electrical energy. This separate source of electrical energy is a source of energy to furnish light in accordance with the impulses impressed on the microphone 1 through sound amplifier 2 and modulated at 3 and finally recorded on a photo-sensitized motion picture film 4 enclosed in a sound recording motion picture camera 5, as shown in Figure 1 of the drawmgs.

In Figure 2, I have shown a sound amplifiber 6 which amplifies sound which is taken from a motion picture film running at suit-- able speed passing a suitable photo-electric cell with a suitable light penetrating the sound track of the motion picture film contained in projection machine 7. The photoelectric cell aforesaid changes a light frequency to a sound frequency. When the light or llght impulses are impressed upon it, these nnpulses are amplified at 6, passed through the wires 8 and out through the horn 9. A perforated motion picture screen 10 is disclosed to allow sound to penetrate the same and I have also shown a fader 11 for fading the sound which also controls the volume, as appears obvious.

In Figure 3 of the drawings I have disclosed one method of achieving the desired results as heretofore set forth and desired to be accomplished by my improved method. The numerals 14 and 15 represent a high frequency mechanical buzzer. The current through this buzzer is adjusted to a flow which is just sufficient to operate it. The solenoid of this buzzer also acts as the primary of atransformer. The secondary winding is connected across the two spark-gap points 17 The high frequency impulses flowing through the primary induced voltages of a higher order than the secondary winding and cause high frequency spark discharges across the spark-gap points 17 The audio impulses coming from the amplifier 12 and through the transformer 13 are superimposed upon the primary current of the solenoid. By this'means the intensity of the spark discharge across the points 17 is varied in accordance with the strength of the sound impulses from the amplifier 12.

In Figure 4 I have shown a slight modification of the disclosure of Figure 3. In this form of the invention, a voltage step-up transformer 19 is interposed. Otherwise, the construction in this modification is the same as that shown in Figure 3 and described hereabove, there being provided the amplifier 18, the mechanical buzzer of high frequency represented by the numerals 20 and 21 and the points 23 across which there is providedthe spark discharge.

A mechanical buzzer, referred to above in Figures 3 and 4, which produces frequencies above 15 thousand cycles is desirable. It has been found, however, that a 10 thousand cycle buzzer frequency is entirely practical since the attenuation at this frequency in recording reduces this high frequency below audibility.

In Figure 5 I have shown a preferred method. In this case a vacuum tube 27 is used to generate high frequency impulses. The sound impulses from the amplifier 24 modulate these high frequency oscillations. In this view, the coils are represented bythe numerals 25 and 26 between the amplifier and the oscillator. The resultant modulated high frequency signals are amplified as to voltage to a high value by means of the coil 29 and impressed across the terminals of the open spark discharge electrodes 30.

In Figure 6 I have shown a slight modification over the disclosure in Figure 5 in which a single electrode is shown and the corona discharge into the air is utilized. In this form Of the invention the amplifier is designated' by the numeral 24; i the numerals 25 .7

and 26 designate coils; the numeral 27 designates a vacuum tube:- used to generate high frequency impulses and 'thenumerals 28 and 29represe'nt coils as appears obvious.

corona discharge described in connection with'the device illustratedqm Figure 6.3

In Figures 8 to 12, inclusive, Ihaveshown similar hook-ups with various forms of lenses. and lens combinations. Up to the light discharge, the hook-ups are the same and for that reason, similar reference characters will be used throughout the views covered by Figures 8 to 12, inclusive. The numeral 32 designates the sound imput microphone from which the sound impulses are amplified through connection with the am-' plifier 33. These sound impulses leave the sound amplifier in the formof audio-frequency impulses in accordance with the impulses nnpressed on said microphone, and

are modulated intohigh frequency electrical energy through the modulating and oscillating circuit 34. This highvfrequency electrical energy is then discharged in the form of light at the point 35.

I use various ways andmeans for obtaining superfine lines of light to expose a motion picture film as will be seen from Figures 8 l to 12, inclusive, and as will be hereinafter specifically described. In Figure 8, I have shown a condensing lens 36 just forward of the are 35. Light passing through this lens is caused to pass through the cylindrical lens 37 where the light is reduced to a hair line. Light then passes through a suitable adjust able slit 38 which also reduces the light lines and said light lines are further reduced to superfine lines of light by means of the reduction lens combination 39,-resulting in a motion picture of sound impulses photographically impressed at a suitable location on a motion picture film4.

JIn Figure 9, I have shown the adjustable slit 40 as one contact and the light from the lamp 35 is discharged through said slit.

From the slit the light is caused to pass through the cylindrical lens 41 and is then still further reduced by being passed through a lens combination 42, resulting in the sound impulses photographically impressed at a suitablelocation on the film 4.

, In Figure 10, the light impulses from the lamp 35 are first passed through a suitable prism 43, which has four of its sides opaqued so as to condense the said light impulses into 1t and ground therein so as to have a razorlike edge for the light impulses to form a superfine line of light as they are passed therefrom. This superfine line of light is then passed through a suitable lens combination 44 which, obviously, results in motion picturefof sound impulses impressed on the film 4. g

"I'nFigure 11, only a prism 43isprovided forwardiof thearc 35 which prism is opaqued on four si'des-so asfto condense the light imlpulses passed into it and ground therein, propassed through a space formedbetween two.

pieces of metal 45 which may be stationary or adjustable, as desired, so as to reduce the photographically very fine hair lines of light to superfine lines 7 of light. The cylindrical lens 44 is connected with the metal pieces 45 bymeans of a'cushion or spring 46 so as to make up any variation in thickness of the motion picture film 4 which is in contact with the members 45. It will be seen, therefore, that these superfine lines of light will be retained in focus at all times and the sound impulses photographically impressed on said film.

In Figures 13 to 18, inclusive, I have shown the results of my sound recording method in the form of sound tracks on photo-sensitized motion picture films. In Figure 13, the film 4, which is of the sixteen millimeter width,

I have shown sound tracks 4a and 4?) at both,

4a inside the sprocket holes adjacent thepicture.

In Figure 16, I have disclosed a thirtyfive millimeter film 4'in which the sound track 4a covers the entire width of the film within the area margined by the sprocket holes.

In Figure 17, I have shown a seventy-two millimeter film 4 with a single sound track 4a inside the sprocket holes.

In Figure 18, I. have shown the film 4 of standard gauge with the picturerunning horizontally and a single sound track 4a within the sprocket holes adjacent the picture. a

From the foregoing description of the construction of my improved method, the manner of applying the same to use will be readily understood and it .will be seen that I have details of construction and changes in .e-lec-' trical hook-ups and changes in designs for electrical light discharges, may be'resorted to, Without departing. from the spirit or sac- 5 rificing any of the principles of the inven-' tion.

Having thus described my invention, what I claim is:

1. An apparatus for producing a highly 1'0 actinic light for recording purposes compris ing a high frequency mechanical buzzer, inductively coupled means for stepping up the high frequency voltage impulses across the solenoid of the buzzer, unshielded discharge 

